Tube nest manufacture



.Nov. 29, 1949 w. HUBER wuanmsw MANUFACTURE 3 Sheets-Sheet 1 Filed July3, 1945 INVENTQR 14 4; 775/? HUBER BY OW, M ail- J. ATTORNEYS Nov. 29,1949 w. HUBER 2,489,888

TUBE NEST MANUFACTURE Filed July 5, 1945 3 Sheets-Sheet 2 000000000000ooooaooooogo I 0000000000000000000 o Wgq 266 INVENTOR a WALTfR HUBER BYQM, 64 mm ATTORNEYS Nov. 29, 1949 w HUBER 2,489,888

TUBE NEST MANUFACTURE Filed July 3, 1945 3 Sheets-Sheet 3 lNVENTOR W/ILT5 HUBER BY aim-W, QM; M321.

ATTORNEYS Patented Nov. 29, 1949 TUBE NEST MANUFACTURE Walter Huber,

to Sulzer Freres,

Switzerland Winterthur, Switzerland, assignor Societe Anonyme,Winterthur,

Application July 3, 1945, Serial No. 603,014 In Switzerland September23, 1944 Claims. (Cl. 113-112) The invention relates to a method ofconstructing a nest of parallel tubes which are supported on each otherby welded bridges and are attached at both ends to tube end walls. Themethod consists in that the tube end walls and the tubes are held by atemplate scaffolding during the insertion of the bridges, some or all ofthe tubes which are heated by welding being cooled by means of a coolingmedium while some or all of the tubes only slightly or not at all warmedby welding are heated by means of a heating medium. In this way theeffect can be obtained that during the manufacture of a nest any warpingof the nest due to non-uniform heating and the stresses arisingtherefrom can be completely avoided.

For carrying out the method a scaffolding can be provided on whichtemplates are attached which hold the tubes at least over part of thecircumference of the nest and the tube end walls in the positioncorresponding to the design of the nest.

Both the cooling medium and the heating medium are preferably conductedthrough the tubes of the nest. During welding itself it is advisable tointerrupt the flow of cooling medium through the tube on which weldingis being done. Between the cooled and the heated tubes the tubes of atleast one layer may contain a medium which neither absorbs nor gives offheat, or an insulating substance may be pressed into them. Themanufacture of the tube nest may be facilitated by setting the tubesbetween which bridges are to be made at the right distance from eachother by means of wedges before the bridges are made.

If three or more welded bridges are provided for a single tube, it isadvisable to arrange the bridges of one tube layer in staggered fashionin such a way that not all of them are applied to one tube at the sametime, further bridges being simultaneously applied to neighbouring tubesof the same layer. The tubes of two neighbouring layers may be inspectedfor leakages by means of a pressure medium before a further layer issupported on one of the first two layers. When the bridges have beenmade, the tubes may be fixed, for instance by inserting them into thetube end walls. When this is done the tubes may be expanded in theregion of the bores in the tube end walls by means of a pressure mediumintroduced into the interior of the tubes.

In the device for applying the invention templates may be attached whichhave the form of at least a part of the circumference of the nest andare held by the scaffolding. It is also possible for template 'beams tobe provided which have openings to fit the tubes of a whole layer. Thetemplate scaffolding preferably has, to the sides of the tube nests,pillars to which the template beams and templates can be attached. Theselateralpillars may have apertures which a'low the template beams to befixed as desired at different heights, the apertures corresponding tothe positions of the single tube layers. Distributing and collectingcasings for supplying and leading off the heating medium may also bemovably laid on the tube end walls on both sides. A movable distributingpipe may also be provided for supplying the cooling medium, and fromthis supply pipes may lead to the single tubes of at least one layer ofthe nest. It is expedient for these supply pipes to be provided withclosing members through which the supply of cooling medium to the tubesof the nest can be interrupted, for instance during the insertion of thewelding bridges. A movable distributing pipe may also be provided forthe pressure medium used for detecting leakages, and from this pipesupply pipes lead to the single tubes of at least one layer of the nest.The supply' pipes may have, at the end introduced into the tubes of thenest, sealing means which are pressed against the tube surface by thepressure of the pressure medium supply itself. At the ends of the tubesopposite to the ends connected to the distributing pipe for pressuremedium, stoppers may be provided which seal the tubes at this end.

The invention is described in more detail below with the aid of thedrawings. Fig. 1 shows a nest of tubes under construction in a sideelevation, Fig. 2 the same in partial cross-section, and Fig. 3 the samein a front elevation. Fig. 4 shows part of a template, a template beamand a lateral supportin pillar to a larger scale. Fig. 5 shows to astill larger scale the application of the wedges used to ensure theright distance between tubes. Fig. 6 shows the insertion of the singlewelded bridges, Fig. 7 the nest of tubes from above with the arrangementfor detecting leakages. Finally Fig. 8 shows on a larger scale a part ofthe arrangement employed for supplying pressure medium in the leakagetest.

For constructing the nest of tubes a template scaffolding is employedwhich has three longitudinal beams I, 2 and 3, by which the lateralpillars 5o 4 and 5, the underlying supporting templates 5 and finallythe overlying spacing template beams I are held in place. At the ends ofthe template scaffolding, supporting and positioning templates 8 and 9are attached, and in these the tube end walls l0 and II, respectively,are inserted. Durpoints 26d, etc.,

3 ing-the insertion oi the welded bridges the tubes l2 and the tube endwalls l and ii are held in the position corresponding to the design orthe nest by this template scafiolding. A cooling medium is meanwhilesupplied through a distributing pipe l3 to some of the tubes which areheated by welding, while other tubes, which are only slightly or not atall warmed by the welding are. heated by a heating medium suppliedthrough the distributing casing II.

It is appropriate to employ as a cooling medium air from the atmospherewhich is introduced into the distributing pip i3 through. vthe pipe l5by means of a supply device not shown in the drawing. Fromthedistributing pipe single supply pipes 16 lead into the tubes of thetop layer requiring to be cooled. In order to enable the supply ofcooling medium to be interrupted temporarily. for instance during theinsertion oithe welded bridges between the tubes, closing members I! arealso provided in the supply pipes Ii Air also serves as heating medium,being introduced into a heating device I9 with the aid of a fan I 8 andconducted in heated state through the pipe 20 into the distrib tingcasing I. It is expedient for the pipe20 to ave articulated Joints notshown in detail in th drawings, in order to enable the position of hecasing H to be continually adapted to the age which the construction ofthe tube nest has reached. After the heating medium has flowed throughthe lower layers of the nest of tubes l2, it is collected by the casing2| and returned to the fan It through the pipe 22, which is alsoequipped with articulated joints.

The design of the lateral pillars 4 and 5, the templates 6 and thetemplate beams 1 is shown in the detail Fig. 4. The templates 6 have theform of a part of the circumference of the tube nest under construction.The outermost tubes of the nest are introduced into the indentations ofthis template. The template beam 1 also has indentations correspondingto the distance between the tubes of one tube layer.

With the aid of bolts inserted in the apertures 23 in the pillars l andin apertures 01' the mplate beam I the latter can always be kept theposition which corresponds to the layer of bes inserted at the top. Inorder to secure the right distance between the tubes l2b already welded(Fig. 5) and the tubes l2a not yet provided with welded bridges, wedges24 are driven between these tubes and press the tubes l2a tight into theindentations 25 of the template beam 1.

For making the welded bridges the tube layer l2a not yet welded iscooled with the aid of the cooling medium. The layer of tubes l2bcontains stagnating air which neither absorbs nor gives off heat. Thelower layers I20, however, have heating medium flowing through them. Ifnecessary an insulat ng material, for instance asbestos sheeting,asbestos or glass wool, may also be introduced between the tube layersHo and III) or I 2b and l2c. The insertion of the welded bridges beginsin the centre of the tube layer first only the welded bridges 26a (Fig.6) in the middle are made. When these bridges have been completed thewelded bridges 2611 are made at the same time on the same and theneighbouring tube in staggered fashion. when these have been completed,the welded bridges lie are simultaneouslymade. Then-follow in a furthersimultaneous working bridges are welded in to the outer circumference atthat side of the nest of tubes. Obviously, during the insertion of thewelded bridges in the direction are made at the same time on each tube.

The welded bridges can be produced by autogapplied is already preheatedby the front end of the flame, while at the same time the danger ol thenewly applied material flowing away behind the flame is considerablydiminished. During the aflixed to the tube end wall both ends. Theexpansion stance with the aid of known expanders.

openings of the tube When the welded bridges have been applied to allthe tubes of two layers l2a, I2b, the tubes of these layers are testedfor leakages. For this purpose a pressure medium is supplied by apressure pump through the pipe 21 distributing ducted to the tubes ofone tube layer through the supply pipes 29. On the other side the endsof the tubes are sealed with the aid of plugs 30 and a bridge piece 3|,so that the tubes under pressure can be tested for leakages. Thedistributing pipe 28 (Fig. 8) has single connections 32 whose of metallaid between the tubes and welded tothem.

I claim:

1. The -method of constructing a nest oi parallel tubes spaced from oneanother by welded bridges and attached at their ends to tube end wallswhich comprises placing the tube end walls in their mutual, final,assembled relation in a template scaffolding, successively introducingsingle layers of tubes into said end walls, holding the tubes of thelast-introduced layer of tubes onto which bridges are to be welded intheir mutual,

final, assembled relation by said template scaffolding, welding in thesupporting bridges between the tubes of said last-introduced layer oftubes and the last previously introduced layer of tubes before the nextsuccessive layer of tubes is introduced, and simultaneously with thewelding-in of each layer of tubes maintaining tubes of that layer onwhich the welding-in of the bridges between them and the last previouslyintroduced layer of tubes has been completed in heat exchange with acooling medium to absorb heat developed in those tubes as a result ofthe welding operation, and heating the last previously-inserted layer oftubes on which the welding-in of all the bridges has been completed bycontact with a heating medium.

2. The method of constructing a nest of parallel tubes as set forth inclaim 1 in which the spacing by the template scafiolding of the tubes between which bridges are being made is supplemented by wedges.

3. The method of constructing a nest of parallel tubes spaced from oneanother by welded bridges and attached at their ends to tube end wallswhich comprises holding the tube end walls in their mutual, final,assembled spaced relation, successively introducing single layers oftubes into said end walls, holding the tubes of the last-introducedlayer of tubes onto which the bridges are to be welded in their mutual,final, assembled spaced relation, welding in the supporting bridgesbetween the tubes of said lastintroduced layer of tubes and the lastpreviously introduced layer of tubes before the next successive layer oftubes is introduced, and simultaneously with the welding-in of eachlayer of tubes maintaining tubes of that layer on which the welding-inof the bridges between them and the last previously introduced layer oftubes has been completed in heat exchange with a cooling medium toabsorb heat developed in those tubes as a result of the weldingoperation, and heating the last previously inserted layer of tubes onwhich the welding-in of all of the bridges has been completed by contactwith a heating medium.

4. The method of constructing a nest of paral- 6 lel tubes as set forthin claim 3 in which tubes of the layer being welded-in but on which thewelding-in of the bridges has not yet begun also are coolingsimultaneously with the welding-in of other tubes of that layer.

5. The method of constructing a nest of parallel tubes as set forth inclaim 3 in which the heating medium is passed through the tubes to beheated.

6. The, method of constructing a nest of parallel tubes as set forth inclaim 3 in which the cooling medium is passed through the tubes to becooled.

7. The method of constructing a nest of parallel tubes as set forth inclaim 3 in which the tubes of the layer of tubes last previouslyintroduced prior to the layer of tubes being welded-in enclose astagnant medium.

8. The method of constructing a nest of parallel tubes as set forth inclaim 3 in which at least three bridges are to be welded to the tubes ofthe layer of tubes being welded-in, and in which the bridges arewelded-in in such a staggered fashion that only a part of the totalnumber of bridges to be welded to any tube are welded-in at a time,while further bridges are being welded to neighboring tubes.

9. The method of constructing a nest of parallel tubes as set forth inclaim 3 in which the tubes of the successive layers of tubes are fixedin the tube end walls after all the bridges have been secured to them.

10. The method of constructing a nest of paralleltubes as set forth inclaim 3 in which insulating material is inserted between the tubes beingcooled and the tubes being heated.

. WALTER HUBER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,745,485- Harter Feb. 4, 19301,751,865 Lewis et a1. Mar. 25, 1930 1,931,679 Price Oct. 24, 19332,107,435 Birmingham Feb. 8, 1938 2,186,641 Jones Jan. 9, 1940 2,267,619Strom Dec. 23, 1941 2,303,473 Jones Dec. 1, 1942 2,332,368 BurtenshawOct. 19, 1943

